Improvement in the manufacture of belt-knives



BENJAMIN F. RADFORD.

improvement in the Manufacture of Belt Knives.

- Patented Dec 19, 1871.

UNITED STATES PATENT FF IGE.

IMPROVEMENT IN THE MANUFACTURE OF BELT-KNIVES.

Specification forming part of Letters Patent No. 121,963, dated December19, 1871.

To all whom it may concern:

Be it known that I, BENJAMIN F. RADFORD, of Hyde Park, in the county ofNorfolk and State of Massachusetts, have invented an Improvement in theManufacture of Belt-Knives; and I do hereby declare that the following,taken in connection with the drawing which accompanies and forms part ofthis specification, is a description of my invention sufficient toenable those skilled in the art to practice it.

My invention relates to an improved method of forming a straight edgeupon a belt-knife or knife-blade or blank, which straight edge is to besubsequently beveled and sharpened to constitute the cutting-edge.

Before my invention such knives, made up of one strip of steel havingits ends j oined, or of several strips joined together end to end, havebeen brought to straight or approximately straight edges by first makinga line near the edge to be trimmed with a straight-edge rule or scale,and then shearing ofl' the edges of the plate up to this line. Thismethod, besides involving exceedingly laborious and carefulmanipulations, is at best very imperfect, or but imperfectly attains theedge desired,'it being impracticable to produce a continuous straightline entirely around the belt. To produce good work with such a knife itis indispensable that the cutting-edges should be straight, and thegreater the degree of perfection in such edges the better does the knifeoperate.

In my invention I obtain such straight edges (from which to form thestraight cutting-edge) by mounting the beltknife or knife forming bandor blade upon pulleys formed with crowning peripheries, the apexes ofwhich will cause the belt to run truly upon the pulleys; and to operateupon the edges of the belt thus mounted, I apply a stationarycutting-tool held in a suitable head or stock, and at the side of one ofthe pulleys, and so that the cutting-edge or point shall be at adistance from the center of the adjacent pulley equal to half the widthof the knife. As the driving-pulley is rotated the belt is actuated, andthe tool cuts the belt to a perfectly straight edge. It is in thismethod of trimming the belt-knife or band, and in the combination withthe crowning pulleys of the cutting-tool, that my invention primarilyconsists.

The drawing represents a machine for trimming a belt-knife or band inaccordance wlth my invention. A shows a plan of the machine. B i

is a side elevation of it.

a denotes a bed, upon which are the housings for the journals of twoshafts, I) c, carrying pulleys d 0, upon which pulleys the belt ismounted and by which pulleys it is driven. Each pulley is formed with acrowning or angling periphery,

as seen at A, the angle f being at the center of V the pulley. As thebelt is driven its inner side rides upon the crown or angle of thepulleys, and the tension causes the center of the band to travel trulyupon the angle, or without any lateral movement. The bearings of one oreach pulley may be made adjustable, to increase or lessen the tension ofthe belt. At one end of the bed is a head-stock, g, in which is clampeda tool-stock, It, carrying a cutting-tool, i. The tool is clamped insuitable position for its point to out either at the side or edge of theband, or into the surface thereof; but in either case the point is fixedas regards a vertical plane running through the apexes of the twopulleys, and cuts the band to an edge parallel to this plane, or, inother words, to an edge perfectly straight, the entire continuous orendless length of the band. The tool-stock may be arranged to slide inthe head-stock, and the latter may be a slide-rest, adjustable on a restor slide, it, and this slide may be adjustable upon another rest, 1, sothat toward or from the pulley, and laterally with respect thereto, thetool-stock may be freely slid to bring it to a cutting position, and therest I may swivel upon a pin, m, to throw the tool up toward or awayfrom the pulley. By moving the tool-stock from one side of the pulley tothe opposite one, either edge or both edges of the band may be straightedged. In connection with the belt-driving pulleys and edgetrimmingtool, grinder-wheels no may be employed to grind the opposite surfacesof the knife-blade.

I claim- The described method of trimming the edges of endless orbelt-knives or bands.

BENJ. F. RADFORD.

